Electric vehicles

[johnb80]

Urine may be sterile when it leaves, but it plays a huge part in the nitrogen cycle, breaking down into ammonia and its by products and is a seriously good plant fertiliser - commercially made nitrogen fertilisers take the nitrogen directly from the air and are massively energy intensive to produce. As far as the solids go, grazing animals don't produce the best dung, just a lot of it - think of chicken or pig manure, both famous for their value in agriculture/horticulture and both from omnivores (by nature at least). When you use "farmyard manure" in your garden, the bigger part of the value of it is in the urine that has soaked into the straw and broken it down. You can turn principle this to your advantage by peeing in your compost heap, which will help it heat up to destroy pathogens and speed up the composting process.
Some treated human waste does still make it to the land, though without looking it up, I'd be guessing if I said how much.

Thanks for the info, it is food for thought (no pun intended).

 

[paulrbarnard]

It always used to be used to great benefit, only stopped with the introduction of flush toilets and let's not forget that the largest amount of waste we produce is in the form of urine, which is hugely beneficial to growing stuff.

It’s amazing that what we flush away today was a thriving business for centuries.

 

[Phil Pascoe]

In China the "night soil" was used as manure - that's why the Chinese don't tend to use salad crops and vegetables uncooked.

 

[Ozi]

As far as fertiliser goes, we all produce significant quantities of it every day (some more than others...!) then spend huge amounts of money and use lots of scarce water to treat it and throw it away, though I accept that some of it does end up on the land.. Would it not make much more sense to see all that "waste" as a valuable resource of methane for fuel and manure for the fields? It would go a long way towards cleaning up the rivers too.

A significant proportion already does. A lot of methane is harvested both from sewage and landfill then used to generate electricity. After bio digestion sewage ends up as "Cake" which has to be allowed to cool which entails it giving off a lot of ammonia to become "black earth" a very sterile product that is then spread on fields.

When the process is followed fully and all works well the only real pollution is the ammonia. Obviously we hear of many instances where things go wrong and rivers get fouled mainly because we lack the infrastructure to handle rain surges.

 

[Ozi]

Until a cheaper way is developed for harvesting the Hydrogen AND an efficient way of storing / transporting Hydrogen it simply will not happen. It's way too expensive, storage tanks are extremely heavy and the pressures involved are dangerously high.

The storage tanks are much liter than you would expect, agreed the pressures involved are frighteningly high and compression requires a lot of energy, but I have seen the results of crash and fire testing on automotive tanks and been pleasantly surprised.

Aye, take a look at the work done by Toyota on the same thing with massively different results. JCB have a resonable argument for fuelling plant and equipment on a building site and the expense Hydrogen may be acceptable in this usage case but not for day to day transport. Have you seen the take up of JCB's Hydrogen offerings? there is almost zero interest.

Very different systems. Toyota use hydrogen in fuel cells and have sold hardly any as there is not the infrastructure to support ownership YET. JCB face a very different problem, I don't think anyone has the first idea how to make a battery powered earth-mover, they produced an IC engine designed to run of hydrogen and proved by designing from scratch rather than converting that efficient operation was possible. For either to be viable requires a regular supply and distribution of green hydrogen at or below the cost of diesel and we are nowhere near that yet.

There is a lot of work currently being done on hydrogen power for buses and other fleet vehicles. The justification here is that there are many inner city bus depots. If you have ever worked in one you will know space is at a premium. An electric bus takes time to charge when it is unavailable for service, so to maintain service you need more busses - where do you put them. Secondly they would need huge amounts of power, running in additional capacity through a city is difficult and costly. Hydrogen may provide an answer to these issues and also reduce vehicle weight which is a benefit. IF this succeeds then the production of hydrogen becomes more viable the cost comes down and availability makes other uses viable. Which in turn makes it cost effective to install more wind generation as power at peak generation can be used rather than being a problem leading to more power being available at times of lower output.

It's hard to see how it could be more attractive, charging overnight at 5p kWh giving 1p per mile fuel cost or from solar energy making it free.


Im sure youre right there are a lot of fringe industries surrounding the oil industry but necessity is the mother of invention, we will find ways when need is established to either manage without the fertiliser or make the fertiliser by other processes.

Agreed necessity is the mother of invention. I refer to a report from the CEGB written in the early 1980s. Some very competent engineers proved that the national grid could not be stable with more than 10% renewable energy.

That's the last twelve months power supply. Some very competent engineers many with the CEGB fixed that. The tinny orange box is power returned from storage - more work to be done.

 

[johnb80]

The storage tanks are much liter than you would expect, agreed the pressures involved are frighteningly high and compression requires a lot of energy, but I have seen the results of crash and fire testing on automotive tanks and been pleasantly surprised.

The tanks are NOT lighter than I expect, theyre very thick metal items that weigh a lot. The fact that you need more Hydrogen than fossil fuels further hinders Hydrogen operation. To hold 5kg of Hydrogen the tank weighs in at 100kg and that is sufficient fuel for around 270 miles in a fuel cell equipped vehicle.. If you run the fuel in a converted ICE then the range drops to around 130 miles with a fuel that costs at very least 3 x the cost of fossil fuels. So whilst crash testing may impress the weight and the cost of fuel will not.

Very different systems. Toyota use hydrogen in fuel cells and have sold hardly any as there is not the infrastructure to support ownership YET.

Toyota as well as the fuel cell powered vehicles also tried converting existing ICE as a concept with dreadful results.

Have a look at this guy, great explanations.

JCB face a very different problem, I don't think anyone has the first idea how to make a battery powered earth-mover, they produced an IC engine designed to run of hydrogen and proved by designing from scratch rather than converting that efficient operation was possible.

Thats the problem, how do you measure 'efficient operation' Hydrogen as a fuel is not efficient compared to fossil fuels, the energy in it is about 1/3. The cost of manufacture is way higher, its an absolute non starter in every respect other than emissions.

For either to be viable requires a regular supply and distribution of green hydrogen at or below the cost of diesel and we are nowhere near that yet.

Exactly what I said previously.

There is a lot of work currently being done on hydrogen power for buses and other fleet vehicles. The justification here is that there are many inner city bus depots. If you have ever worked in one you will know space is at a premium. An electric bus takes time to charge when it is unavailable for service, so to maintain service you need more busses - where do you put them.

They charge up at bus stations where theyre at the end of their route like the Tesla Semi.

Secondly they would need huge amounts of power, running in additional capacity through a city is difficult and costly.

You would think so except in London for example, standing charges on electricity meters are considerably lower than the rest of the UK

Hydrogen may provide an answer to these issues and also reduce vehicle weight which is a benefit.

That will not happen due to fuel tank weight

IF this succeeds then the production of hydrogen becomes more viable the cost comes down

It still takes the same amount of electricity to get the Hydrogen whether your getting 1 tonne or a 10000 tonnes, the energy required is 3x the amount that the Hydrogen produces when it's used. Why waste such a lot of energy?

Have a look at this with prof David Cebon, he knows his stuff and explains it in a very easy manner. (start at 06:30 to avoid Llewelyns rabbiting). Hydrogen currently is not viable.

and availability makes other uses viable. Which in turn makes it cost effective to install more wind generation as power at peak generation can be used rather than being a problem leading to more power being available at times of lower output.

Omit the wasteful Hydrogen process, store it in batteries 3x more efficient.

Agreed necessity is the mother of invention. I refer to a report from the CEGB written in the early 1980s. Some very competent engineers proved that the national grid could not be stable with more than 10% renewable energy.

Just goes to show how things change.

View attachment 188490That's the last twelve months power supply. Some very competent engineers many with the CEGB fixed that. The tinny orange box is power returned from storage - more work to be done.

Im not sure what your graphic is really portraying. The live stats from the grid regularly show high % renewables.

 

[Ozi]

The tanks are NOT lighter than I expect, theyre very thick metal items that weigh a lot. The fact that you need more Hydrogen than fossil fuels further hinders Hydrogen operation. To hold 5kg of Hydrogen the tank weighs in at 100kg and that is sufficient fuel for around 270 miles in a fuel cell equipped vehicle.. If you run the fuel in a converted ICE then the range drops to around 130 miles with a fuel that costs at very least 3 x the cost of fossil fuels. So whilst crash testing may impress the weight and the cost of fuel will not.



Toyota as well as the fuel cell powered vehicles also tried converting existing ICE as a concept with dreadful results.

Have a look at this guy, great explanations.





Thats the problem, how do you measure 'efficient operation' Hydrogen as a fuel is not efficient compared to fossil fuels, the energy in it is about 1/3. The cost of manufacture is way higher, its an absolute non starter in every respect other than emissions.


Exactly what I said previously.


They charge up at bus stations where theyre at the end of their route like the Tesla Semi.


You would think so except in London for example, standing charges on electricity meters are considerably lower than the rest of the UK


That will not happen due to fuel tank weight


It still takes the same amount of electricity to get the Hydrogen whether your getting 1 tonne or a 10000 tonnes, the energy required is 3x the amount that the Hydrogen produces when it's used. Why waste such a lot of energy?

Have a look at this with prof David Cebon, he knows his stuff and explains it in a very easy manner. (start at 06:30 to avoid Llewelyns rabbiting). Hydrogen currently is not viable.




Omit the wasteful Hydrogen process, store it in batteries 3x more efficient.


Just goes to show how things change.

Im not sure what your graphic is really portraying. The live stats from the grid regularly show high % renewables.

Just going to comment on some of this.

The tanks I have tested were made of composite materials and very lite weight.
Toyota tried to convert an IC engine and failed which is why JCB started from scratch and succeeded.
You can't just charge busses at the end of the route without additional busses many finish one shift and are taken straight out on the next.
You can't necessarily get enough power to the bus station to run all the chargers, it would be easier to replace the road tanker that currently brings in diesel with one bringing in hydrogen. This is why there are currently hydrogen busses running around the test tracks at MIRA.
I don't know where you get the 3x figure from but it is very optimistic but the return of petrol is around 3% and that seems to work

Good night